It looks like it's the .40 size...there should be a red half moon aluminum placard stuck to the side of the case (that would indicate it's size ) but it's missing?

They are somewhat rare, but having been run, that will depreciate it's value considerably.

Do you have the box?

My guess would be between maybe 50 and 100 bucks...depending on how much it's been run, and how badly someone wants it.